: The best I have come up with so far is to go through all the terms
: gotten from the IndexReader.terms() and filter on field(). That works
you're basically on it, but look at the IndexReader.terms(Term) method
which allows you to start with a specific term, and then bear in mind that
the TermEnum goes in order, which means all of the terms for a single
field will come sequentially, so as soon as you see a field name other
then the one you are interested in, you know you can stop.
if you look at the code for RangeFilter you'll see a good example of
iterating over a TermEnum for a single field ... what you want is
effectively the same the work RangeFilter would do when the bounds are
both null.
-Hoss